March 2006, British Columbia: The ferry Queen of the North was making a routine transit. The mate was chatting with the helmsman and missed a course change. Catching the error, he ordered a larger course change to compensate. But an unfamiliar steering system had just been installed. The helmsman was unable to switch from autopilot to manual steering. The vessel struck an island and sank with loss of life.

July 2001, Ohio River: The towboat Elaine G was underway. A change of watch was taking place as fog settled in, just before dawn. In the moments it took to complete the watch change, neither officer noticed a recreational boat ahead. Nor did those on the smaller boat recognize that they no longer had the river to themselves. The Elaine G ran down the smaller boat, killing all six aboard.

August 1993, Tampa Bay, Florida: The inbound tug Seafarer was pushing a barge of jet fuel shortly before dawn. The officer on watch told a slower vessel ahead that he did not intend to overtake. Moments later, the tug’s captain took over the watch. He put the throttles full ahead and began overtaking the slower vessel. Meanwhile, on an outbound ship, the captain turned the bridge over to a harbor pilot, one mate relieved another and the pilot became involved in a radio call concerning his next assignment. All three vessels collided at a bend in the channel. The jet fuel erupted, blowing out wheelhouse windows. The outbound ship, flooding in multiple places, was driven aground to avoid sinking.

Accidents like these never come down to one thing. But what these three have in common is that various transitions interfered with the ability of highly experienced individuals to maintain situational awareness and take effective action.

Situational awareness is perceiving what is going on around you, identifying which developments have the potential to affect you, and forming a course of action. Maintaining situational awareness requires continuous reassessment, a feat that we largely, but not always, accomplish intuitively. Fatigue, distraction and complacency are well-known barriers to situational awareness.

Transitions are different. Transitions have a way of spreading situational awareness more thinly, muddling priorities as we attempt to bridge the gap from the way things were to the way they are. Anticipating and managing transitions is central to maintaining situational awareness for anyone on the water. Here are some areas where problems can arise.

Equipment: Researching and buying a piece of navigational kit is fun. We do it on the premise that the new one will be superior to the old one. But we knew the old one so well — its buttons, its knobs and its limitations. The manual was dog-eared and highlighted. That familiarity led directly to a certain efficiency in using the equipment. New, improved equipment may eventually leave you better off, but in the short term you may be fumbling, swearing and losing the big picture. If you have just replaced a key piece of equipment, take time to learn it before you need it under pressure.

Visibility: The shifting moods of the sea and sky are part of the attraction of being on the water. But the mutability of nature presents challenges. In particular, fog and darkness inhibit sensory awareness, forcing us to rely more on instruments (radar, chart plotter, sounder) to maintain situational awareness. We are fortunate to have such resources, but when we shift from visual cues to screens and digits, situational awareness can lag and we may miss a new development. Alternately, when visibility improves and you are still peering at a screen, you may miss something important that the naked eye would have caught.

On a technical note, a radar picture that has been adjusted for fair weather will be degraded by rain or choppy seas unless the operator has the presence of mind to activate rain and sea suppressions. Conversely, a radar picture that has been adjusted for rain and sea clutter will be less sensitive when those conditions have passed. This is just another manifestation of how the sea is a transition-rich environment that calls for quick-footedness in every respect.

Twilight: Twilight is a subset of visibility. The very word speaks to the way in which day and night briefly coexist, twice a day. The human retina is equipped with two types of photoreceptors: cones and rods. Cones are active during daylight hours and provide color sensitivity. Rods are low-light receptors that are good for peripheral vision, motion detecting and depth perception, but not color. As day turns into night, and vice versa, our eyes are transitioning from one type of vision to another. You may recall moments at twilight when it was difficult to pick things out and gauge their distance. This is related to the way the eye works, and it creates a period of vulnerability as we try to perceive what is going on around us.

Another twilight-related transition pertains to console displays. Console lighting, including electronics, should be dimmed as darkness falls so as to preserve night vision, but then we must remember to increase brightness come morning so we can see the information being displayed.

Weather: More than most things, weather has a way of changing plans. Any time you change a plan, short of turning around and heading straight back to the marina, you commence a dalliance with unintended consequences. Plan A was well thought out — the anchorage, the wind direction, the amount of daylight at arrival, the tide, the current, the under-keel clearance, the distance. Plan B, if you had one, received no such treatment, and was less than ideal in the first place; that’s why it was Plan B. As the thought process warms to Plan B, you may notice a certain amount of “hoping for the best” creeping in. Hoping for the best is not a plan, but it is often the handmaiden to a fiasco born of an ill-considered change of plan.

Conversely, a change of weather may find a person hanging on to Plan A out of sheer stubbornness, and in defiance of facts. Making the shift to Plan B isn’t always easy, but recognizing that the moment is upon you to fish or cut bait is part of understanding the significance of transitions.

Other transitions that challenge situational awareness include operating in unfamiliar waters, going from open water to confined waters, moving from low-traffic to high-traffic situations, or having people aboard who don’t know your boat, your way of doing things and your terminology. It’s all manageable. But having respect for how transitions affect awareness can help you avoid a situation where your head is in the old game, when a new game has already begun.

This article originally appeared in the September 2018 issue of Soundings.